I have issues with dirty water in filter area and dishes not coming clean. This is a new dishwasher. Old one had similar issues so I think it is the drain and not dishwasher. Is the drain setup ok? Would it be better going to disposal? There is no possibility of adding an air gap.
Update: The upright pipe is what I think is an attempt at a loop..air gap thing. The plastic drain hose from the dishwasher comes out of the dishwasher..across the bottom of the cabinet. Up the side of that white pipe where it becomes clamped to a copper pipe. That empties into the white pipe which goes back down to the bottom of the cabinet and out its own drain. Thanks!